I'm not sure I'd call him a con artist but moreso doesn't go the extra step and get his own products tested before selling to the public (which 99% of brands don't do btw)...it's expensive and in reality I think most brands fear what the results may be so they just trust the raw martial supplier and/or manufacturer.
But just testing 1 ingredient, turk, shouldn't be all that expensive maybe $500-$750 AT BEST (and could be way way less for all I know). It's when you have 10+ ingredients in a product is where it can really get costly.
99.999999% of the popular online brands (that we in this group buy from often) don't test their finished products.
Is this the best practice? No
.
Is this 99% the norm? Yes.
Do I think he willingly sold bogus or under dosed turk? No.
The bigger issue is just claiming turk is even worth it...IMHO, its not. Just take creatine.